Die casting machine



DIE CASTING MACHINE Filed Oct. 6. 1934 3 I I I 2.94 fl FR 2; 2a 57 wH625: INV T0.

56.6. mafliw 772% ATTORNEYS.

Patented Sept. 28, 1937 PATENT OFFICE DIE CASTING MACHINE William A.Parker, Erie, Pa.

Application October 6, 1934, Serial No. 747,244

2 Claims.

The present invention is designed to improve die casting machines andhas particular reference to the manner of charging and discharging themold and involves preferably providingone of the mold parts withengaging surfaces so that the casting may be uniformly retained in oneof the mold parts as the mold is opened so that the mold discharge meansmay be readily applied to the casting after the mold is suitably opened.The invention also involves the provision of a charging system in whichone end of the charging passage is chilled and the opposite end heatedso that the separation of the .molten metal from the chilled metal ofthe casting may be localized.

In this way the chilled plug of the metal in the passage may bewithdrawn with the casting as the mold is opened and the molten metalmay be returned to the supply. The invention also involves anautomatically actuated die casting machine which is continuous in itsoperation and automatic in charging and discharging the mold. Featuresand details of the invention will appear more fully from thespecification and claims.

A preferred embodiment of the invention is illustrated in theaccompanying drawing as follows:-

Fig. 1 shows a side elevation of the machine, partly in section.

Fig. 2 a section on the line 2-2 in Fig. 1. Fig. 3 an enlarged view ofthe mold charging tube.

Fig. 4 a schematic view of the'driving mechanism.

Fig. 5 a section of the mold with the parts in closed position.

Fig. 6 a section on the line 6-6 in Fig. 5.

I marks the machine frame and 2 legs supporting the frame.

er 4, the burner being adapted to heat the molten metal receptacle 5. Acharging cylinder 6 is supported by the receptacle and communicates withthe receptacle through a port I. A plunger 8 operates in the cylinder,closing the port 'I in its downward stroke so as to force the-moltenmetal to the mold. A piston rod 9 extends from.

A heating chamber 3 is provided with a burn (01.22 10) discharge openingI'Ia. A connection I8 also extends to the valve I5 and leads to thelower end of the cylinder I I. This passage is also alternatelyconnected by the ports I! with the inlet passage I6 and the dischargepassage Ila so that 5 as the valve is operated in proper timing withrelation to the other operations of the machine by the mechanismhereinafter described the piston Ill is forced downwardly carrying withit the plunger 8 and expelling a charge for the mold. 10 At the properinterval the piston 8 is returned with an initial suction action in itsreturn movement to 'facilitate the separation of the molten metal fromhe chilled metal of the mold and to uncover the port so as to permit aninflow of 15 molten metal. In the initial movement of the piston, thepiston is retarded by the extension I2 which restricts the incoming airso that the filling of the air above the piston I0 is comparativelyslow. This is desirable in that the plunger ,20 does not violently expelthe molten metal from the port I and gives a gradual start to the flowin the passage. A communicating port I9 extends from the lower end ofthe cylinder 6 up to the charging tube 20. The charging tube is fixed 25on the walls of the receptacle at the discharge end of the port I9. Thecharging tube has a restriction 2I formed by the taper 22 which has itssmaller end at the restriction. This charging tube is arranged in anopening 23am the mold supporting plate 23. A mold member 24 as shown hasa mold cavity 25 and has a seat 24w adapted to seat on a seat 20a at theend of the charging tube. This connection permits of the ready chargingof the mold. The mold member is provided with chambers 26 adapted toreceive cooling liquid through connections (not shown). The moldsupporting plate 23 is mounted on brackets 21 extending from the burnerchamber 3. The hot gases from the burner are discharged through anopening 30. and deflected into the opening 23a. As a result the chargingtube is subjected at one end to the heat of the hot gases and at theopposite end to the chilling effect of 45 the cooling liquids in thechamber 26. There is,

- therefore; a chilling of the metal in the one end 25a of the moldmember is also tapered so as to readily facilitate the removal of thecharging plug of metal which may be attached to the casting.

By this structure a fixed relation is maintained through the chargingpassage to the mold, the mold end of this passage being tapered topermit the direct axial removal of the solidified plug of metal attachedto the casting. The remaining portion of the passage returns through thepassage to that part of the passage within the receptacle so as toacquire and maintain the desired temperature. This is accomplishedwithout any intervening valves, without the breaking.

of the connection between castings, and affords a very definiteuniformity of product. Lower guide rods 28 extend from the plate 23 to across member 30a. The cross member is fixed on a gear case 30 which caseis mounted on the frame I. Guide rods 28 extend beyond the cross member39a and into a rear pressure head 3| to which they are secured. An upperguide rod 29 is secured to and extends between the supporting plate 23and the head 3|. A reciprocating head 32 has bearings 33 which areslidingly mounted on the rods 28 and 29. A toggle lever has members 34and 35 pivotally connected by pins 36. The forward end of the lever ispivotally connected at 31 with the reciprocating head 32. The rearmember 35 is pivotally connected with the head 3| by a pin 38. A link 39is connected by a pin 49 with the lever 34 adjacent to the pivotalconnection at 36. The link is connected by a crank pin 4| with a crank42. The crank 42 is fixed on a drive shaft 43. As indicated in Fig. 2,the toggle lever mechanism and crank are duplicated at each side of themachine, there being a crank at each end of the shaft 43. A worm gear 45is fixed on the shaft 43 and meshes with a worm 46. The worm is arrangedon a worm shaft 41 and the shaft 41 is journaled in bearings 48 in thecase 30. A driving pulley 49 is fixed on the worm shaft and is drivenfrom a belt 50 from a pulley The pulley 5| is fixed on a rotor shaft 52of a motor 53. Through this mechanism it will'readily be seen that thecrank is rotated and through its rotation reciprocates the link 39swinging the toggle lever so as to open and close the mold. This togglelever mechanism is brought to a position to close the mold with themembers 34 and 35 in substantial alinement. As indicated in Fig. 4, thecrank is at the points a and b when the parts 34 and 35 are in exactalinement. They are brought from slightly below that point in the travelof the crank represented at c. In actual operation the mold ismaintained in closed position from the point 11 to the point e, thespring of the included mechanism permitting the very slight variation inthis interval. In other words, while there is a continuous motion of thecrank and While the toggle lever in its straightened position positivelyholds the molds under pressure and in closed position a dwell in thisclosed position is accomplished by making the closed position in thepart of the crank travel where the movement from the crank to the togglelevers and the movement of the toggle levers results in very littlevariation in the straight line arrangement of the toggle levers. Thus asimple, powerful driving connection is provided, comparatively fastduring the. opening and closing movements and with a dwell of suflicientlength over a sufficient period to procure the chilling of the castingin the mold.

A movable member 54 of the mold has complementary mold parts completingthe mold with of the molding surfaces.

the cavity 25. This is provided with water cooling chambers 55 connectedwith a source of cooling liquid (not shown) The movable mold member isprovided with a socket 56a which, with the mold closed, is directlyopposite the charging passage 25a. This socket is connected by a lead 56which connects the charging passage with the mold cavity. The socket 56ahas its walls shaped to so engage the metal of the plug formed in thesocket as to assist in withdrawing the casting from the stationary moldmember. The mold member 54 is connected by straps, or plates 51 with ablock 58 secured on the head 32 so that the mold member 54 reciprocateswith the head. A knock-out block 59 is slidingly mounted in the spacebetween the member 54 and the block 58 on pins 60 which extend from themember 54 to the block 58. Knock-out pins 6| and 62 extend from theknock-out block 59 through the mold member into position to engage thecasting and discharge it from the mold. One of these pins 62 operates onthe end of the plug formed in the socket 56a. Push rods 63 are slidinglymounted in perforations 64 in the head 32 and extend from the knock-outblock 59. An abutment 65 issecured on the rod 29 preferably adjustableby means of a securing screw 66. A thrust pin 61 ex -ends from theknock-out block 59 through the mold member 54 and is positioned toengage the face of the mold member 24 as the head 32 with the moldmember 54 is advanced.

The molding operation is as follows: The movable member 54 is movedforward, closing the mold. With this forward movement, the pin 61engages the mold member 24 and arrests the knock-out block 59 so as toretract the knock-out pins 6| and 62 and bring them back to the facesAfter the mold is charged and the metal chilled the member 54 isretracted opening the mold and in this rearward movement the push rods63 come into engagement with the abutment 65, thus arresting theknockout block 59 prior to the completion of the rearward movement ofthe mold member. With the continued movement of the mold member thepush-out pins 6| and 62 are projected through the mold member 54, thusdisengaging the casting from the mold after which the operation ofclosing the mold is. repeated.

The air on the cylinder is automatically controlled. A rock arm 68 isconnected with the valve plug l5a. A rod 69 connects the arm 68 with abell crank lever pivotally mounted or. a pin 1| in the frame. A rod 12extends from the bell crank lever to a rock arm 13. The rock arm ismounted on a pin 14 mounted on the gear case 30. Rock arms and 16 arefixed with the rock arm 13 and provided with rollers 11 at their ends. Acam 18 is arranged on the end of the cran 1 42 and the rollers 11 are inthe path of the cam 16 as the crank is rotated. As the mold is closedthe crank reaches the arm 15 and throws, through the connectingmechanism, the valve plug l5 to connect the upper end of the cylinderwith the air supply. The immediate downward movement of the piston andwith it the plunger 8 charges the mold. After the mold is charged and atthe completion of the dwell the cam 18 reaches the roller on the arm 16and reverses the valve |5 so as to exhaust the upper end of the cylinderand connect the lower end of the cylinder with the air supply. Theplunger 8 is then withdrawn and this withdraws the molten metal makingthe break somewhere in the charging tube 20, the exact position of thebreak depending somewhat The piston I is considerably larger than theplunger 8 so that there is a very decided pressure diflerential.- Thismay be made as much as desired depending on the available air pressurefor operating the piston and the proper pressure to be exerted on themolten metal in the mold. This pressure is increased by the fact thatafter the extension I2 leaves the socket I3 the air flow on the pistonis rapid and there is a very great acceleration of the piston so that itreaches the point where the mold is filled at a very considerablevelocity and this gives to the metal as it fills the mold an added andfinal pressure shock through the inertia of the plunger and piston. Inthis way the mold is filled rapidly and with a very high final pressure.

It will be noted in the present structure that the mold has a fixedmember and a movable member and that the knock-out action on the formedcasting is'accomplished through a single reciprocating mechanism. Thusthe operating mechanism is very much simplified.

This application is in part a continuation of application, Serial Number627,195, filed by me Aug. 1, 1932.

What I claim as new is:

1. In a die casting machine, the combination of a mold; a molten metalsupply receptacle; a fixed connection between the receptacle and themold; a plunger cylinder in the receptacle having an inlet port formolten metal; a plunger in the cylinder operating over the port; a.power cylinder above the plunger cylinder; apiston operating in thepower cylinder connected with the plunger; a cylinder extension ofsmaller diameter than the power cylinder; a piston extension operatingin the cylinder extension and effecting the initial movement of theplunger, the piston completing the movement of the plunger, and forcingthe molten charge into the mold; and means reversing the plunger toreverse the pressure on the connection to sever the molten metal fromthe metal of the mold.

2. In a die casting machine, the combination of a mold; a molten metalsupply receptacle; a connection between the receptacle and the mold;means for forcing molten metal through said connection into the moldcomprising a cylinder having a supply port leading from the receptacleand a plunger in the cylinder operating to force the metal from thecylinder through the connection into the mold; and means retarding theacceleration of the plunger during the closing of the port.

W. A. PARKER.

